An ultrasound examination in the second month of pregnancy, which indicates fluid in the uterine cavity, suggests that there may be a possibility of preterm miscarriage. This is because sometimes when there is inflammatory irritation, or when there is a small amount of shedding of the endometrium, a small amount of bleeding around the gestational sac, and when there is exudation of fluid around the gestational sac, this may cause fluid to accumulate inside the uterine cavity. Generally, in such a case, if it is not particularly much, you should pay attention to good bed rest when you go home, do not overly frequent strenuous exercise, and you can take oral medication for fetal preservation treatment. As for when to stop the medication, the time to stop the medication should be decided according to the fluid in the uterine cavity. If there is a lot of fluid in the uterine cavity, which is greater than two centimeters or even three centimeters, it is recommended to be hospitalized for fetal preservation treatment to ensure the health and stability of the fetus.